The present application is generally related to components and systems of optical communication buses.
Optical networking using plastic optical fibers (POF) may provide advantages over networking using copper or other metal wiring. Categories of plastic optical fiber include plastic clad silica (PCS) fiber, single core plastic optical fiber, or multi-core plastic optical fiber. Plastic optical fiber networking may have lower installation and maintenance costs. Moreover, because plastic optical fibers are lighter than metal wires that would be needed to carry an equivalent amount of data, using plastic optical fibers may result in appreciable weight savings. The weight savings may be significant for networks aboard vehicles, such as aircraft, where the weight savings may result in reduced fuel consumption and lower emissions.
In some scenarios, a number of line replaceable units (LRUs) may need to be connected to each other. For example, a number of line replaceable units at the front of a vehicle may need to be connected to a number of components at the back of a vehicle. Connecting each line replaceable unit to each other line replaceable unit may result in an unreasonably large number of connections between line replaceable units. Additionally, many of the connections between line replaceable units may be long, resulting in a number of long connections. If all of these connections are in the form of copper wires, the resulting space and weight of the connections alone may be burdensome for the vehicle. Electrical data buses have been used to connect line replaceable units. A single data bus can eliminate some of the weight and size of electrical connections between line replaceable units. In general, optical communication fibers, such as glass optical fibers (GOF) and plastic optical fibers, can be lighter and contained in smaller spaces than electrical wiring. However, implementing optical communication systems is not as simple as merely replacing all electric wiring with optical fibers.
Plastic optical fibers exhibit high transmission capacity, have excellent electromagnetic interference (EMI) noise immunity, are light weight, have high mechanical strength and have outstanding flexibility. Due to these properties, plastic optical fibers are used in data communications, as well as decoration, illumination, and similar industrial applications. Plastic optical fibers are also larger in diameter as compared to glass optical fibers. Due to its larger diameter, plastic optical fibers exhibit much greater tolerance to fiber misalignment than glass optical fibers. Because of this large misalignment tolerance, plastic optical fiber-based fiber optic networks have lower maintenance and installation costs. In aerospace platforms plastic optical fibers also greatly reduce the cost of connectors and transceiver components used in an avionics network.
Some optical communication components have been developed. For example, U.S. Pat. No. 7,965,913 describes an optical star rod that includes a hollow cylindrical holding tube for receiving plastic optical fibers (POF) at a front end of the holding tube and a mixing rod at a rear end of the holding tube. The rear end of each POF is affixed to a front surface of the mixing rod. A rear convex surface of the mixing rod is polished and coated with a highly reflective coating to form a convex reflective surface. However, U.S. Pat. No. 7,965,913 does not describe the use of a tapered mixing rod to convey signals from one number of input optical fibers to a different number of output optical fibers.